/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */

/**
 * 
 * @param pListHead ListNode类 
 * @param k int整型 
 * @return ListNode类
 */
struct ListNode* FindKthToTail(struct ListNode* pListHead, int k ) {
    // write code here
    if(pListHead == NULL)
    return NULL;
    if(k==0)
    {
        return NULL;
    }
    struct ListNode* fast = pListHead,*slow = pListHead;
    while(fast&&k--)
    {
        fast = fast->next;
    }
    if(fast == NULL&&k>0)
    {
        return NULL;
    }
    while(fast)
    {
        fast = fast->next;
        slow = slow->next;
    }
    return slow;
}